Editing Mesta (section)

===The Cañadas===
The annual migration was made possible by using ''cañadas'' a system of long-distance pathways used by migrating flocks which occur in those Mediterranean countries that practice transhumance. In Spain, some of the paths that run north–south are known to have existed from the early Middle Ages, although claims of Roman or pre-Roman origin are doubtful,<ref>Klein, pp. 28-9</ref> as the ancient sheepwalks that have been described from Spain are generally relatively short and frequently run from uplands east to the Mediterranean coast, rather than from north to south.<ref>Walker, pp. 41-2</ref> Sheep were generally only part of the mixed farming of cereals and livestock in León and Old Castile before the 12th century, less important than pigs and rarely moved outside their local area.<ref>Pastor de Togneri p.365</ref> The cañadas in León and Old Castile may have developed from an increased range of transhumance that first occurred within those provinces, and which were extended south as the northern boundaries of Muslim states retreated.<ref name="Walker, p.38">Walker, p.38</ref>

The expansion of the cañadas southward has been related to three causes, which may have all played their part, but here is no evidence of large scale transhumance in Extremadura, Andalucía and La Mancha when they were under Muslim rule, so the impetus must have come from the Christian north.<ref>Pastor de Togneri p. 366</ref> From the reconquest of Toledo in 1085 to that of Andalucía, stock raising, particularly of sheep, was developed New Castile, at first by over thirty northern monasteries, bishoprics and churches, many with their summer pastures in the Sierra de Guadarrama, and secondly by the military orders, which received royal grants of pasturelands in the Tagus valley.<ref>Pastor de Togneri pp. 367-9</ref> Documents dated from the late 12th century show that the military Orders were regularly driving their sheep from New Castile into the previously Muslim areas of La Mancha, western Murcia and into the Guadalquivir valley, and it is possible that this transhumance had crossed political boundaries between Christian and Muslim states the before local Christian reconquest.<ref>Butzer, pp.38-9</ref>

The third possible cause relates to transhumance organised by the towns of Castile and León. Southern towns, such as Toledo after its 1085 reconquest, sent their flocks to over-winter in the Guadalquivir valley, accompanied by an armed guard.<ref>Bishko, (1963) p.57.</ref> In addition, there was an expansion of transhumant travel south from Segovia and Burgos at the end of the 12th century and the start of the 13th century using cañadas opened by the monasteries, possibly into what was still Muslim territory.<ref>Pastor de Togneri p. 378-6</ref> However, the victory of Los Navas de Tolosa in 1212 opened the pastures of the Guadiana to all Castilian flocks, not just those of the monasteries and military orders. As the influence of the Castilian urban stockholders increased from the last decades of the 12th century, they increased the numbers of the sheep they were able to support by exploiting these new pastures.<ref>Pastor de Togneri pp.372-4</ref>

The main north–south cañadas, or ''Cañadas Reales'', were those designated by royal charter, although their precise routes may have changed over time, as they were only marked and given a defined width when crossing cultivated land, not when crossing open or untilled land. Both near their north and south termini, numerous minor local cañadas joined into or branched off from the Cañadas Reales.<ref>Klein, pp.18-19</ref> Klein describes three  principal groups of cañadas reales wholly within the kingdom of Castile-León, namely the western, or ''Leonesa'', the central, or ''Segoviana'', and the eastern, or ''Manchega'' groups, running through the cities of León, Segovia and Cuenca respectively.<ref>Klein, p.19</ref> Walker splits the Segovian group, adding a fourth group passing through Soria.<ref name="Walker, p.38"/> The Leonese cañadas terminated in [[Extremadura]] and in the banks of the Tagus and Guadiana rivers, those of Segovia and Soria, which were the major routes, ended in Andalucía and the Manchegan ones in [[La Mancha]] and eastern [[Murcia]]. Some authors divide these groups into nine or ten quite separate routes, but Klein noted the possibility of sheep moving between different branches of the western and central groups.<ref>Cahn, pp.2-3</ref><ref>Klein, p.xviii</ref>

There are very few records of numbers of sheep migrating annually before the early 16th century. In the 16th century, the numbers of migrating sheep recorded annually ranged from 1.7 to 3.5 million, averaging around 2.5 million Merino sheep, but the numbers began to decline in the late 16th and particularly in the early 17th century, a time of warfare in the Low Countries.<ref>García Sanz (1978), pp.292-4</ref> Klein places the start of the Mesta's decadence in the third quarter of the 16th century.<ref>Klein pp. 26-8</ref> During that period, only Merino sheep migrated, but the proportion of Merinos driven south in any year depended on the spring rainfall in the northern pastures and the fluctuating price of pasture in the south. After the [[Eighty Years' War]], transhumant numbers rose again, but to a lower level than in the 16th century. This was not because of a decline in overall numbers of Merino sheep, but a reduction in long-range transhumance and a parallel increase in flocks pastured in their home areas. Non- migratory Merino flocks of southern cities such as Córdoba also expanded and competed with transhumant flocks.<ref>Butzer, pp. 41-2</ref>